Today, fabrication of semiconductor dies or chips commonly includes so-called dicing, i.e. separation of the individual dies or chips from a substrate, typically a wafer substrate or, short, wafer. In the production lines, dicing currently is achieved by means of mechanical sawing of the substrate. Recently, plasma dicing has appeared for the separation of the dies of a wafer, especially for dicing of very small chips on a wafer. Plasma dicing generally involves etching of the wafer.
However, during the etch process, metallizations provided on the wafer, such as, for example backside metallizations of the chips may be slightly etched or impurities may diffuse into the metallizations, metal material may be “kicked out” from the metallization during etching and contaminate the etch chamber, or an uncontrolled polymerization may occur, which may lead to changed etching rates and/or stability characteristics.